1. Technical Field
The present invention relates to a locking mechanism for a telescoping steering column.
2. Description of the Prior Art
A known telescoping steering column for a vehicle includes two relatively movable sections of the steering column. The vehicle steering wheel is supported on one of the movable sections. To adjust the steering column, the driver of the vehicle moves a handle to release the one section for telescopic movement relative to the other section. When the steering wheel is in the desired position, the driver releases the handle, and a mechanical locking mechanism within the steering column prevents further relative movement of the steering column sections.
The two steering column sections often have a splined connection between them. A small gap exists between the two splined parts. As a result, some amount of lash is present in the steering column, adversely affecting the steering feel and control.
It is known to use electrorheological fluid in an energy absorber for an engine mount or another structure having two relatively movable parts. Typical structures incorporating such a fluid are disclosed in U.S. Pat. Nos. 5,176,368 and 5,655,757. Varying the strength of an energy field acting on the fluid can vary the apparent viscosity of the fluid, thus controlling the energy absorption characteristics of the device.
The present invention is an apparatus for supporting a steering wheel of a vehicle. The apparatus comprises a first steering column part and a second steering column part. The first steering column part and the vehicle steering wheel are supported for telescopic movement along an axis between a plurality of different positions relative to the second steering column part. A locking mechanism is interposed between the first steering column part and the second steering column part for locking the first steering column part in a selected one of the plurality of positions. The locking mechanism comprises a fluid having a viscosity which varies in response to an energy field acting on the fluid. The locking mechanism also includes means for varying the viscosity of the fluid by varying the energy field to vary the resistance to movement of the first steering column part relative to the second steering column part.